Leeds were only 12-4 behind at the end of a relatively even first half, but two tries in the first five minutes after the interval made it a damage limitation exercise.
They failed to even keep the score respectable, conceding seven tries in all to the team who had Super League’s second poorest attack – after their own – at the start of round 15.
Rhinos have now conceded 92 points in their last two games, scoring only 20 and a 14th defeat in 17 competitive matches this year will increase the pressure on coach Brian McDermott.
Leeds were forced to field a patched-up side after Rob Burrow (calf) and Mitch Garbutt (back) joined their casualty list and Brett Delaney’s return was put on hold after he suffered a recurrence of a hamstring problem.
Brad Singleton, Luke Briscoe and teenage debutant Sam Hallas were all drafted in after not being named in the initial 19.
Rhinos went ahead, for the third successive game, when Kallum Watkins galloped over from Adam Cuthbertson’s, offload after Keith Galloway and Jordan Lilley had handled.
That was as good as it got in the opening 40 for Leeds, though they did have some chances towards the end of the half and Danny McGuire had a touchdown ruled out by the video referee.
Willie Isa scored both Wigan’s first-half tries, from a pass and then kick by George Williams, Matty Smith converting both.
Williams and Dom Manfredi crossed at the start of the second half, after Ash Handley failed to deal with high kicks and then Ben Flower powered over.
Two more Smith conversions made it 28-4 and Leeds were reduced to 12 players for a spell when Zak Hardaker was sin-binned for a professional foul on Josh Charnley.
Rhinos reduced the deficit during Hardaker’s spell on the naughty step, Mitch Achurch powering over for a well-taken try from another Cuthbertson offload.
Hardaker returned and got over the line with his first touch, but referee Joe Cobb thought it was a dual-movement and video assistant Ben Thaler agreed.
Cobb began the game as a touch judge, but moved into the middle mid-way through the first half when Robert Hicks suffered a calf muscle injury.
Leeds seemed to have stemmed the tide, but they conceded two more tries in the final five minutes, Oliver Gildart and Dan Sarginson going over and Smith converting both.
Leeds remain bottom of the table and will be two points adrift if Huddersfield beat St Helens on Sunday.